Devices for electrical connection of a connecting line to an electrode, in particular a medical engineering skin electrode, are disclosed in DE 37 19 474 A1. Such connecting devices are used, for example, for measurement of physiological signals from living beings, such as heart action voltages (electrocardiogram, EKG). The electrodes are positioned on the patient's skin, by an adhesive, for example, and are connected to an electric connecting line over which the physiological electrical signals are conducted to an evaluating device. The disclosed connecting device operates as a snap fastener connection and is snapped onto the contact pin of the electrode. The contact pin may be a separate element of the conventional electrode or may, for example, form the electrode surface itself in conjunction with a lower side of a plate-shaped base component.
The user places heavy demands of such devices. Thus, making and breaking the connection should be permitted without application of great force, while at the same time producing a durable electric connection of high quality. An obstacle to meeting these requirements is presented by the electrodes being generally mass-produced and being made for one-time use. For these reasons, the connecting heads of the electrodes present only low dimensional accuracy and high tolerances. In addition, the electrode dimensions vary from manufacturer to manufacturer.
Consequently, electrode clamps have been developed as an alternative to the generic devices disclosed. Operating legs are opened against the force of a spring and are mounted on the head of the electrode, electrical contact being established when the electrode clamps are released. The retaining force can be set very effectively by the spring used. As a rule, no problem is encountered in release of the electrode clamps. However, such electrode clamps present the disadvantage that, because of the structural configuration of the operating legs, the contact member has an external shape with multiple surfaces unsuitable for wearing under clothing.